Improvement in atmospheric filters



R. G. LUDLOW. Atmospheric Filter.

Patented Dec.- 25, 1877.*

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.INVENTOR flaw/x67 4M,

ATTORNEY N PETERS, PHOTO-LITNOGRAPHER, WASHINGTON, D C,

UNITED STAT S PATENT OFFICE.

RICHARD O. LUDLOW, OF ST. LOUIS, MISSOIIRI.

IMPROVEMENT IN ATMOSPHERIC FILTERS.

Specification forming pbrt of Letters Patent N0, 198,637, dated December25, 1877; application filed November 17, 1877.

To all whom-"it may concern:

Be it known that I, RIGHARD O. LUDLOW, of St. Louis, in the county ofSt. Louis and State of Missouri, have invented a new and valuableImprovement in Atmospheric Filters; and I do hereby declare that thefollow-.

ing is a'full, clear, and exact description of the construction andoperation of the same, reference being had to the annexed drawings,making a part of this specification, and to the letters and figures ofreference marked thereon.

Figure 1 of the drawings is arepresentation of a front view of myimproved filter, and Fig. 2 is a cross-section thereof.

This invention has relation to improvements in atmospheric filters.

In regions where bituminous coal is used the atmosphere is saturatedwith imperceptible particles of soot, which, when admitted to dwellingsand other buildings, is deposited on walls, furniture, and otherobjects, to their great injury and disfigurement.

The object of my invention is to free the atmosphere of all materialimpurities, and deliver it perfectly pure to the'cold-air ducts ofhotairfurnaces, so that when heated it may pass out of the flues and bedistributed without the injurious effects above stated.

The nature of the invention consists in two frames, fastened togetherface to face, each one within the other, and thensecuredremovablytogether. Between the netting is placed a layer, 0, ofcotton-wool or other suitable material, of suflicient thickness toarrest the particles of soot or dust in the air, and to allow air topass through freely. These frames are placed in a cold-air chamber orduct, and efl'ectually exclude foreign matter from the hot-air chamberof a furnace or other heater.

Being protected from the direct contact of the wind and weather in thesaid chamber or duct, the filter thus formed is perfectly effective ofthe object sought to be produced 5 but when the filter is or must beplaced upon the exterior of a building, I prefer to place a sheet offine gauze, D, (wire preferably,) on the exterior face of the frame,which is exposed to the weather. This serves to arrest the coarserparticles, thereby lessening thefrequency of the necessity of changingthe cotton, and, in great measure, to break the 2. The combination, withthe sheets of network B B and an interposed layer of cottonwool, of asheet of net-work, of a fine mesh, exterior to the sheets B B,substantially as specified.

In testimony that I claim the above I have hereunto subscribed my namein the presence of two witnesses.

RICHARD c. LUDLOW.

Witnesses:

O. P. SAY oR, Enw. WELSH.

